Vapor-induced polyelectrolyte complexation of chitosan/pectin: A promising strategy for the preparation of hydrogels for controlled drug delivery

Abstract

An innovative vapor-induced polyelectrolyte complexation process mediated by the acetic acid vapor is reported in this study as an alternative to preparing hydrogels of chitosan and pectin. Usually, this kind of hydrogel is prepared by the conventional solution mixture method, which results in materials with limited properties. Beyond demonstrating the efficiency of this process, a deep investigated throw light into the structure-properties relationships of these hydrogels, which could be useful to orientate their further application. The different characterization analyses demonstrated that the hydrogels obtained through the polyelectrolyte complexation of chitosan and pectin using this alternative method possess ordered regions within their structures. This configuration results from the packing of the polysaccharide chains due to the strong electrostatic interactions among the charged functional groups, being a direct result of the slow-rate complexation process driven by the vapor-induction. In terms of application, this structural characteristic of the hydrogels prepared by the vapor-induced method was pivotal to controlling and prolonging the release rate of curcumin, which was previously encapsulated into these hydrogels. Moreover, the experimental data for the release of CUR from these hydrogels was well-fitted by zero-order kinetics, differing from the hydrogels prepared through the conventional mixture of chitosan/pectin solutions. In summary, the molecular and microstructural understanding of the polyelectrolyte complexation of chitosan and pectin driven by this original vapor-mediated method raises as an alternative to prepare hydrogels with specific and tailored properties, which can be beneficial for drug delivery applications.